feat(start): recent files as a list, icons or large previews

Three toggles beside the Recent Documents title switch the panel between
the existing list, a grid of thumbnail tiles and one large preview per
file. The choice is kept in the recent section of the app config.

Refs #1494

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

locales/zh-TW/opencadstudio.ftl

@@ -99,6 +99,9 @@ start =
     .no-recent-files = 您開啟的檔案將顯示在此處。
     .browser-storage = 瀏覽器儲存空間
     .keep-recent-files = 保留最近檔案
+    .view-list = 清單
+    .view-icons = 圖示
+    .view-preview = 大型預覽
 
 donation =
     .title = 捐款請求